There's about 19,000 employees so most people, like me, will have no idea about how current affairs broadcasting is actually operated in any way relevant to political bias.
Most of what it technically needs is in place. Everyone in any function is issued with a big brick of a book, the Editorial Guidelines, basically policy on what you can do and say. It's probably public, I'm not sure. If everyone were equally held to account on this it might help. Within recruitment, retention etc as I've experienced it, diversity and equality are taken seriously and it significantly outperforms most private sector organisations, so again there's no reason why there can't be diversity of opinion and background in current affairs. There has been identification of some failings (like 'balance') but not necessarily decisive action, but then this should be no surprise for such a complex oil tanker of an organisation.
I don't know what's feasible in terms of a funding model but I don't like subscription. Public broadcasting is an important public service that should inform, educate and entertain the population, and even an imperfect implementation is better than something designed to benefit its selective subscribers. Lots of decisions, particularly investment, are made with holistic audiences in mind - the viewers/listeners that it doesn't currently have - and that goes out of the window if the remit is merely to provide to opt-in fee-payers. General taxation is one option but this has historically been avoided because it's even more subject to government manipulation.